Today marked the end of classes for me (at least for now). I still have a presentation to give tomorrow and a final exam next Monday, but other than that, I’m free! I’m quite happy to be nearing the end of this phase, and am anxious to get to research. So much of my time has been taken up with TA work and course work that I haven’t been very productive on the research front, although I have managed to finish my MS thesis on Cygnus A.
I still have a few things left to wrap up the semester, mostly related to the observing class for which I am a TA.. grading and computing the final grades. That should be all wrapped up by early next week.
Despite the end of courses, the next week and a half should be quite busy… I have to finish a data reduction/calibration of some of the recently acquired GBT data. Additionally, I still have my 45 minute thesis defense to finish up (and the associated edits for the thesis). After that… vacation!
Last night was the Fan Mountain Observatory Public Night. It started out with some clouds on the horizon, which made target selection difficult. However, about halfway through the night, the clouds cleared out and we were treated with a gorgeous view of the sky. All told, we had about 350 visitors!
I spent half the night talking about the Fan Mountain Observatory Bench Optical Spectrograph (FOBOS), which is the workhorse instrument of the 40″ telescope at Fan Mountain. Most of the talk was explaining what a spectrograph is and how astronomers use them to determine the composition and line-of-sight motion of stars. There was one every 20 minutes or so, so we kept pretty busy. And it’s always nice to see people excited about science.
Both the 40″ and 31″ telescopes had eyepieces on them, giving people and opportunity to look through a large telescope! The view through them is always gorgeous. The Charlottesville Astronomical Society was also on hand with many more telescopes, looking at a variety of objects.
My grandparents were up for the public night and had a good time looking through the variety of telescopes. It was great to see them, even if it was only for a short while.
The semester is starting to wrap up here. As usual, that means things are quite busy. The past few days have been spent working on the final project for our “Interstellar Medium” class. David and I are working on a phenomenon called continuum pumping, which can affect the measured spectrum from a gaseous nebula or active galactic nuclei. The basic idea is that the broad continuum from a star can serve to excite atoms, resulting in increased line emission from hydrogen and some metals.
Our final project can be split into basically two parts… the first is to write down the various equations to describe this phenomenon, make simplifying assumptions and compute the additional line emission when continuum pumping is included. The second part is to use a numerical computer code to simulate a gaseous nebula. I have been primarily working on the first part, and am (hopefully) close to a solution. David has been working on the simulations, using Cloudy to get more accurate values. All in all an interesting project. It is fun pretending to be a theorist 
Pictures from the recent New River Gorge climbing trip have been uploaded to flickr Here are a few of my favorites:
For the whole set of pictures see: New River Gorge Climbing on flickr
As I’ve noted before, I am finishing up a M.S. in Imaging Science from RIT. My research has focused on the infrared emission in the powerful radio galaxy Cygnus A. I’m happy to announce that my thesis is ready for the defense! I will be traveling up to Rochester during the second week of May, and giving my ~45 minute defense and working on a paper to publish the results.
Title and abstract:
Modeling the Infrared Emission from Cygnus A
The Spitzer Space Telescope provides a unique view of the Universe at infrared wavelengths. Improved sensitivity and angular resolution over previous missions enable detailed studies of astrophysical objects, both in imaging and spectroscopic modes. Spitzer observations of active galactic nuclei can help shed light on the physical conditions of the central regions of these active glalaxies.
The nearby radio galaxy Cygnus A is one of the most luminous radio sources in the local Universe. In addition to the high radio power, it is also very luminous in the infrared. Spitzer spectroscopy and photometry of Cygnus A is combined with data from the literature at radio and sub-mm wavelengths and modeled with a combination of: a synchrotron emitting jet, a burst of star formation, and emission from an AGN. The infrared emission in Cyngus A shows contributions from all three processes and the models are able to reproduce the observed emission over almost 5 dex in frequency. Evidence is seen for a break in the synchrotron spectrum in the mid-infrared. The relevant component of the infrared emission suggests Cygnus A has a star formation rate of ~20 M_sun per year. Even in the absence of the AGN, it would still be a luminous infrared source.
Three weeks to go! I’ll post updates as they come…
